Tissue Hydration Influences Bursting Pressure of Fused Arteries

2013 ◽  
Author(s):  
James D. Cezo ◽  
Nicholas Anderson ◽  
Eric Kramer ◽  
Kenneth D. Taylor ◽  
Mark E. Rentschler ◽  
...  
Keyword(s):  
Triple Helix ◽  
Bound Water ◽  
Free Water ◽  
Tissue Temperature ◽  
Bursting Pressure ◽  
Tissue Fusion ◽  
Dipole Interactions ◽  
Ecm Proteins ◽  
Arterial Tissue ◽  
Thermally Driven

Tissue fusion is a complex thermally driven reaction which, through the application of heat and pressure, bonds the extracellular matrix (ECM) of neighboring tissues together. While the mechanism of this reaction is unknown, several theories do exist. Collagen is largely thought to be responsible for the formation of the fusion bond [1–3]. During tissue fusion, as the tissue temperature is elevated (> 100 °C) [4–5], collagen denatures and water is forcibly evaporated out of the tissue [6–11]. Collagen in arterial tissue is comprised of a tightly wound triple helix held in place by crosslinking. Upon denaturation, the crosslinks are broken and the helix unwinds [6–8]. It is theorized that under applied heat and pressure the denatured molecules tangling with adjacent molecules [1], crosslinking to neighboring molecules [2], or a combination of these two mechanisms are responsible for the formation of the tissue fusion bond [3]. Water is also present in the ECM which can be classified as free or bound. Free water is able to diffuse and move freely around the ECM. Bound water is held to ECM proteins through dipole interactions. During tissue fusion, the water is forcibly removed and these charged sites which interact with water are now able to interact with adjacent molecules. These charged sites would not exist if not for the removal of water from the ECM. The goal of this study is to elucidate the importance of water in the formation of the tissue fusion bond.

Determine the Moisture Distribution in Sewage Sludge by Drying Differential

2014 ◽  
Vol 665 ◽  
pp. 404-407 ◽  
Author(s):  
Wan Yu ◽  
Pei Sheng Li
Keyword(s):  
Sewage Sludge ◽  
Interstitial Water ◽  
Bound Water ◽  
Free Water ◽  
High Accuracy ◽  
Moisture Distribution ◽  
Municipal Sewage ◽  
Municipal Sewage Sludge ◽  
Hot Air ◽  
Critical Water Content

Moisture distribution in sewage sludge was considered as the essential of thermal drying. Some methods were given in literatures to test the moisture distribution, but there was no standard method to determine the critical water content between different kinds of water. The municipal sewage sludge was dried by hot air in this work. Based on the drying curve, the derivative of drying rate with respect to dry basis moisture content was brought out to analyze the moisture distribution in sewage sludge. Results show that this method can easily determine the free water, interstitial water, surface water and bound water with a high accuracy. The present work can provide new insight to determine the moisture distribution in sewage sludge, which was still lacking in the literatures.

scholarly journals Testing the effects of basic numerical implementations of water migration on models of subduction dynamics

Solid Earth ◽  
2014 ◽  
Vol 5 (1) ◽  
pp. 537-555 ◽  
Author(s):  
M. E. T. Quinquis ◽  
S. J. H. Buiter
Keyword(s):  
Upper Mantle ◽  
Water Distribution ◽  
Mantle Wedge ◽  
Bound Water ◽  
Free Water ◽  
Water Velocity ◽  
Water Migration ◽  
Creep Flow ◽  
Dehydration Reactions ◽  
Slab Dehydration

Abstract. Subduction of oceanic lithosphere brings water into the Earth's upper mantle. Previous numerical studies have shown how slab dehydration and mantle hydration can impact the dynamics of a subduction system by allowing a more vigorous mantle flow and promoting localisation of deformation in the lithosphere and mantle. The depths at which dehydration reactions occur in the hydrated portions of the slab are well constrained in these models by thermodynamic calculations. However, computational models use different numerical schemes to simulate the migration of free water. We aim to show the influence of the numerical scheme of free water migration on the dynamics of the upper mantle and more specifically the mantle wedge. We investigate the following three simple migration schemes with a finite-element model: (1) element-wise vertical migration of free water, occurring independent of the flow of the solid phase; (2) an imposed vertical free water velocity; and (3) a Darcy velocity, where the free water velocity is a function of the pressure gradient caused by the difference in density between water and the surrounding rocks. In addition, the flow of the solid material field also moves the free water in the imposed vertical velocity and Darcy schemes. We first test the influence of the water migration scheme using a simple model that simulates the sinking of a cold, hydrated cylinder into a dry, warm mantle. We find that the free water migration scheme has only a limited impact on the water distribution after 1 Myr in these models. We next investigate slab dehydration and mantle hydration with a thermomechanical subduction model that includes brittle behaviour and viscous water-dependent creep flow laws. Our models demonstrate that the bound water distribution is not greatly influenced by the water migration scheme whereas the free water distribution is. We find that a bound water-dependent creep flow law results in a broader area of hydration in the mantle wedge, which feeds back to the dynamics of the system by the associated weakening. This finding underlines the importance of using dynamic time evolution models to investigate the effects of (de)hydration. We also show that hydrated material can be transported down to the base of the upper mantle at 670 km. Although (de)hydration processes influence subduction dynamics, we find that the exact numerical implementation of free water migration is not important in the basic schemes we investigated. A simple implementation of water migration could be sufficient for a first-order impression of the effects of water for studies that focus on large-scale features of subduction dynamics.

Bond Strength of Thermally Fused Vascular Tissue Varies With Apposition Force

2015 ◽  
Vol 137 (12) ◽  
Author(s):  
Nicholas S. Anderson ◽  
Eric A. Kramer ◽  
James D. Cezo ◽  
Virginia L. Ferguson ◽  
Mark E. Rentschler
Keyword(s):  
Bond Strength ◽  
Blood Vessels ◽  
Thermal Energy ◽  
Molecular Mechanisms ◽  
Vascular Tissue ◽  
Tissue Temperature ◽  
Tissue Fusion ◽  
Tunica Media ◽  
Adhesive Mechanics ◽  
Bond Strengths

Surgical tissue fusion devices ligate blood vessels using thermal energy and coaptation pressure, while the molecular mechanisms underlying tissue fusion remain unclear. This study characterizes the influence of apposition force during fusion on bond strength, tissue temperature, and seal morphology. Porcine splenic arteries were thermally fused at varying apposition forces (10–500 N). Maximum bond strengths were attained at 40 N of apposition force. Bonds formed between 10 and 50 N contained laminated medial layers; those formed above 50 N contained only adventitia. These findings suggest that commercial fusion devices operate at greater than optimal apposition forces, and that constituents of the tunica media may alter the adhesive mechanics of the fusion mechanism.

Characterization of thin water layers in pulp by tritium exchange. Part 1: Methods development

Holzforschung ◽  
2007 ◽  
Vol 61 (2) ◽  
pp. 115-119 ◽  
Author(s):  
Frances L. Walsh ◽  
Sujit Banerjee
Keyword(s):  
Water Content ◽  
Surface Area ◽  
Tritiated Water ◽  
Bound Water ◽  
Free Water ◽  
Fiber Surface ◽  
Bulk Water ◽  
Methods Development ◽  
A Value ◽  
A New Technique

Abstract A new technique for measuring the monolayer water content of fiber is presented. Tritiated water is added to a pulp/water suspension, whereupon the tritium partitions between the bulk water and the pulp. In the pulp phase the tritium can exchange with free water, bound water, and with hydroxyl and other protons present in the pulp matrix. The free water in the pulp is then removed by displacement with acetone. The tritium remaining in the pulp is mostly associated with tightly bound water, with a small fraction being tied up with the exchangeable hydrogen in pulp. The procedure provides a value of 10% for the tightly bound water content of hardwood or softwood fiber, either bleached or unbleached. If this water is assumed to cover the fiber surface as a monolayer, then an estimate of the wet surface area of the fiber can be obtained. This estimate compares well with independent measurements of surface area.

scholarly journals Water Adsorption to Leaves of Tall Cryptomeria japonica Tree Analyzed by Infrared Spectroscopy under Relative Humidity Control

Plants ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1107
Author(s):  
Wakana A. Azuma ◽  
Satoru Nakashima ◽  
Eri Yamakita ◽  
Tamihisa Ohta
Keyword(s):  
Hydrogen Bonding ◽  
Relative Humidity ◽  
Cryptomeria Japonica ◽  
Water Adsorption ◽  
Bound Water ◽  
Free Water ◽  
High Water ◽  
Water Molecules ◽  
Cross Sectional ◽  
Tissue Properties

Leaf water storage is a complex interaction between live tissue properties (anatomy and physiology) and physicochemical properties of biomolecules and water. How leaves adsorb water molecules based on interactions between biomolecules and water, including hydrogen bonding, challenges our understanding of hydraulic acclimation in tall trees where leaves are exposed to more water stress. Here, we used infrared (IR) microspectroscopy with changing relative humidity (RH) on leaves of tall Cryptomeria japonica trees. OH band areas correlating with water content were larger for treetop (52 m) than for lower-crown (19 m) leaves, regardless of relative humidity (RH). This high water adsorption in treetop leaves was not explained by polysaccharides such as Ca-bridged pectin, but could be attributed to the greater cross-sectional area of the transfusion tissue. In both treetop and lower-crown leaves, the band areas of long (free water: around 3550 cm−1) and short (bound water: around 3200 cm−1) hydrogen bonding OH components showed similar increases with increasing RH, while the band area of free water was larger at the treetop leaves regardless of RH. Free water molecules with longer H bonds were considered to be adsorbed loosely to hydrophobic CH surfaces of polysaccharides in the leaf-cross sections.

Swelling Behaviors and Water States of Fibrous Membranes Electrospun from PHBV-g-PVP

2012 ◽  
Vol 482-484 ◽  
pp. 1478-1482
Author(s):  
Wei Wang ◽  
Jian Da Cao ◽  
Ping Lan
Keyword(s):  
Water Absorption ◽  
Fiber Diameter ◽  
Bound Water ◽  
Free Water ◽  
Great Capacity ◽  
Electrospun Membranes ◽  
Dsc Characterization ◽  
Fibrous Membranes ◽  
Water Swelling ◽  
Swelling Behaviors

Fibrous membranes with a fiber diameter between 320 and 460 nm were electrospun from poly(3-hydroxybutyrate-co-3-hydroxyvalerate)-graft-poly(N-vinylpyrrolidone) (PHBV-g-PVP) and their specific water absorption behaviors were investigated for biomaterial purposes. Water swelling experiments indicate that all samples have a great capacity for water uptake, while a remarkable overshoot occurs for the membranes electrospun from PHBV-g-PVP other than those from PHBV. DSC characterization indicates that only non-freezable bound water and free water can be distinguished in all electrospun membranes.

Temperature Measurement Methods During Direct Heat Arterial Tissue Fusion

2013 ◽  
Vol 60 (9) ◽  
pp. 2552-2558 ◽  
Author(s):  
James D. Cezo ◽  
Eric Kramer ◽  
Kenneth D. Taylor ◽  
Virginia Ferguson ◽  
Mark E. Rentschler
Keyword(s):  
Temperature Measurement ◽  
Measurement Methods ◽  
Tissue Fusion ◽  
Arterial Tissue

Water migration in poplar wood during microwave drying studied by time domain nuclear magnetic resonance (TD-NMR)

Holzforschung ◽  
2017 ◽  
Vol 71 (11) ◽  
pp. 881-887 ◽  
Author(s):  
Xinyu Li ◽  
Yulei Gao ◽  
Minghui Zhang ◽  
Ximing Wang ◽  
Xinyue Wei
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Time Domain ◽  
Bound Water ◽  
Free Water ◽  
Microwave Drying ◽  
Drying Rate ◽  
Drying Time ◽  
The Time Domain ◽  
Nuclear Magnetic

AbstractThe migration of bound water and free water has been investigated during microwave drying of wood by the time domain nuclear magnetic resonance (TD-NMR) technique. Both the heartwood (hW) and sapwood (sW) of Beijing poplar (Populus beijingensisW. Y. Hsu) and Qingpi poplar (Populus platyphyllaT. Y. Sun) were studied. The microwave drying is characterized by a fast drying rate, and there is a linear relation between moisture content (MC) and microwave drying time (t). The drying rate of free water is about 2.7 times more rapid than that of bound water. The spin-spin relaxation time (T2) revealed that most of the water was free water situated in smaller pores. The irregular T2 signal amplitudes of free water in hWs indicated that fractional water in smaller pores was transferred into bigger pores during drying.

Energy-Based Tissue Fusion for Sutureless Closure: Applications, Mechanisms, and Potential for Functional Recovery

2018 ◽  
Vol 20 (1) ◽  
pp. 1-20 ◽  
Author(s):  
Eric A. Kramer ◽  
Mark E. Rentschler
Keyword(s):  
Surgical Techniques ◽  
Connective Tissues ◽  
Tissue Fusion ◽  
Minimally Invasive Surgical ◽  
Dipole Interactions ◽  
Vessel Sealing ◽  
Vascular Ligation ◽  
Cross Links ◽  
Molecular Bonding

As minimally invasive surgical techniques progress, the demand for efficient, reliable methods for vascular ligation and tissue closure becomes pronounced. The surgical advantages of energy-based vessel sealing exceed those of traditional, compression-based ligatures in procedures sensitive to duration, foreign bodies, and recovery time alike. Although the use of energy-based devices to seal or transect vasculature and connective tissue bundles is widespread, the breadth of heating strategies and energy dosimetry used across devices underscores an uncertainty as to the molecular nature of the sealing mechanism and induced tissue effect. Furthermore, energy-based techniques exhibit promise for the closure and functional repair of soft and connective tissues in the nervous, enteral, and dermal tissue domains. A constitutive theory of molecular bonding forces that arise in response to supraphysiological temperatures is required in order to optimize and progress the use of energy-based tissue fusion. While rapid tissue bonding has been suggested to arise from dehydration, dipole interactions, molecular cross-links, or the coagulation of cellular proteins, long-term functional tissue repair across fusion boundaries requires that the reaction to thermal damage be tailored to catalyze the onset of biological healing and remodeling. In this review, we compile and contrast findings from published thermal fusion research in an effort to encourage a molecular approach to characterization of the prevalent and promising energy-based tissue bond.

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